// --------------------------------------------------------------------------
// Copyright (c) 1998-2004, Drew Davidson and Luke Blanshard
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// Redistributions of source code must retain the above copyright notice,
// this list of conditions and the following disclaimer.
// Redistributions in binary form must reproduce the above copyright
// notice, this list of conditions and the following disclaimer in the
// documentation and/or other materials provided with the distribution.
// Neither the name of the Drew Davidson nor the names of its contributors
// may be used to endorse or promote products derived from this software
// without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
// FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
// COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
// INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
// BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
// OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
// AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
// OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
// THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
// DAMAGE.
// --------------------------------------------------------------------------
package com.vonchange.ognl;

import com.vonchange.ognl.enhance.UnsupportedCompilationException;

import java.lang.reflect.Array;
import java.math.BigDecimal;
import java.math.BigInteger;
import java.util.Collection;
import java.util.Enumeration;

/**
 * This is an abstract class with static methods that define the operations of OGNL.
 * 
 * @author Luke Blanshard (blanshlu@netscape.net)
 * @author Drew Davidson (drew@ognl.org)
 */
public abstract class OgnlOps implements NumericTypes
{

    /**
     * Compares two objects for equality, even if it has to convert one of them to the other type.
     * If both objects are numeric they are converted to the widest type and compared. If one is
     * non-numeric and one is numeric the non-numeric is converted to double and compared to the
     * double numeric value. If both are non-numeric and Comparable and the types are compatible
     * (i.e. v1 is of the same or superclass of v2's type) they are compared with
     * Comparable.compareTo(). If both values are non-numeric and not Comparable or of incompatible
     * classes this will throw and IllegalArgumentException.
     * 
     * @param v1
     *            First value to compare
     * @param v2
     *            second value to compare
     * @return integer describing the comparison between the two objects. A negative number
     *         indicates that v1 < v2. Positive indicates that v1 > v2. Zero indicates v1 == v2.
     * @throws IllegalArgumentException
     *             if the objects are both non-numeric yet of incompatible types or do not implement
     *             Comparable.
     */
    public static int compareWithConversion(Object v1, Object v2)
    {
        int result;

        if (v1 == v2) {
            result = 0;
        } else {
            int t1 = getNumericType(v1), t2 = getNumericType(v2), type = getNumericType(t1, t2, true);

            switch(type) {
            case BIGINT:
                result = bigIntValue(v1).compareTo(bigIntValue(v2));
                break;

            case BIGDEC:
                result = bigDecValue(v1).compareTo(bigDecValue(v2));
                break;

            case NONNUMERIC:
                if ((t1 == NONNUMERIC) && (t2 == NONNUMERIC)) {
                    if ((v1 instanceof Comparable) && v1.getClass().isAssignableFrom(v2.getClass())) {
                        result = ((Comparable) v1).compareTo(v2);
                        break;
                    } else {
                        throw new IllegalArgumentException("invalid comparison: " + v1.getClass().getName() + " and "
                                + v2.getClass().getName());
                    }
                }
                // else fall through
            case FLOAT:
            case DOUBLE:
                double dv1 = doubleValue(v1),
                dv2 = doubleValue(v2);

                return (dv1 == dv2) ? 0 : ((dv1 < dv2) ? -1 : 1);

            default:
                long lv1 = longValue(v1),
                lv2 = longValue(v2);

                return (lv1 == lv2) ? 0 : ((lv1 < lv2) ? -1 : 1);
            }
        }
        return result;
    }

    /**
     * Returns true if object1 is equal to object2 in either the sense that they are the same object
     * or, if both are non-null if they are equal in the <CODE>equals()</CODE> sense.
     * 
     * @param object1
     *            First object to compare
     * @param object2
     *            Second object to compare
     * @return true if v1 == v2
     */
    public static boolean isEqual(Object object1, Object object2)
    {
        boolean result = false;

        if (object1 == object2) {
            result = true;
        } else {
            if ((object1 != null) && object1.getClass().isArray()) {
                if ((object2 != null) && object2.getClass().isArray() && (object2.getClass() == object1.getClass())) {
                    result = (Array.getLength(object1) == Array.getLength(object2));
                    if (result) {
                        for(int i = 0, icount = Array.getLength(object1); result && (i < icount); i++) {
                            result = isEqual(Array.get(object1, i), Array.get(object2, i));
                        }
                    }
                }
            } else {
                // Check for converted equivalence first, then equals() equivalence
                result = (object1 != null) && (object2 != null)
                        && (object1.equals(object2) || (compareWithConversion(object1, object2) == 0));
            }
        }
        return result;
    }
    
    public static boolean booleanValue(boolean value)
    {
        return value;
    }
    
    public static boolean booleanValue(int value)
    {
        return value > 0;
    }
    
    public static boolean booleanValue(float value)
    {
        return value > 0;
    }
    
    public static boolean booleanValue(long value)
    {
        return value > 0;
    }
    
    public static boolean booleanValue(double value)
    {
        return value > 0;
    }
    
    /**
     * Evaluates the given object as a boolean: if it is a Boolean object, it's easy; if it's a
     * Number or a Character, returns true for non-zero objects; and otherwise returns true for
     * non-null objects.
     * 
     * @param value
     *            an object to interpret as a boolean
     * @return the boolean value implied by the given object
     */
    public static boolean booleanValue(Object value)
    {
        if (value == null)
            return false;
        Class c = value.getClass();

        if (c == Boolean.class)
            return ((Boolean) value).booleanValue();

        if ( c == String.class )
            return Boolean.parseBoolean(String.valueOf(value));

        if (c == Character.class)
            return ((Character) value).charValue() != 0;
        if (value instanceof Number)
            return ((Number) value).doubleValue() != 0;
        
        return true; // non-null
    }

    /**
     * Evaluates the given object as a long integer.
     * 
     * @param value
     *            an object to interpret as a long integer
     * @return the long integer value implied by the given object
     * @throws NumberFormatException
     *             if the given object can't be understood as a long integer
     */
    public static long longValue(Object value)
        throws NumberFormatException
    {
        if (value == null) return 0L;
        Class c = value.getClass();
        if (c.getSuperclass() == Number.class) return ((Number) value).longValue();
        if (c == Boolean.class) return ((Boolean) value).booleanValue() ? 1 : 0;
        if (c == Character.class) return ((Character) value).charValue();
        return Long.parseLong(stringValue(value, true));
    }

    /**
     * Evaluates the given object as a double-precision floating-point number.
     * 
     * @param value
     *            an object to interpret as a double
     * @return the double value implied by the given object
     * @throws NumberFormatException
     *             if the given object can't be understood as a double
     */
    public static double doubleValue(Object value)
        throws NumberFormatException
    {
        if (value == null) return 0.0;
        Class c = value.getClass();
        if (c.getSuperclass() == Number.class) return ((Number) value).doubleValue();
        if (c == Boolean.class) return ((Boolean) value).booleanValue() ? 1 : 0;
        if (c == Character.class) return ((Character) value).charValue();
        String s = stringValue(value, true);

        return (s.length() == 0) ? 0.0 : Double.parseDouble(s);
    }

    /**
     * Evaluates the given object as a BigInteger.
     * 
     * @param value
     *            an object to interpret as a BigInteger
     * @return the BigInteger value implied by the given object
     * @throws NumberFormatException
     *             if the given object can't be understood as a BigInteger
     */
    public static BigInteger bigIntValue(Object value)
        throws NumberFormatException
    {
        if (value == null) return BigInteger.valueOf(0L);
        Class c = value.getClass();
        if (c == BigInteger.class) return (BigInteger) value;
        if (c == BigDecimal.class) return ((BigDecimal) value).toBigInteger();
        if (c.getSuperclass() == Number.class) return BigInteger.valueOf(((Number) value).longValue());
        if (c == Boolean.class) return BigInteger.valueOf(((Boolean) value).booleanValue() ? 1 : 0);
        if (c == Character.class) return BigInteger.valueOf(((Character) value).charValue());
        return new BigInteger(stringValue(value, true));
    }

    /**
     * Evaluates the given object as a BigDecimal.
     * 
     * @param value
     *            an object to interpret as a BigDecimal
     * @return the BigDecimal value implied by the given object
     * @throws NumberFormatException
     *             if the given object can't be understood as a BigDecimal
     */
    public static BigDecimal bigDecValue(Object value)
        throws NumberFormatException
    {
        if (value == null) return BigDecimal.valueOf(0L);
        Class c = value.getClass();
        if (c == BigDecimal.class) return (BigDecimal) value;
        if (c == BigInteger.class) return new BigDecimal((BigInteger) value);
        if (c == Boolean.class) return BigDecimal.valueOf(((Boolean) value).booleanValue() ? 1 : 0);
        if (c == Character.class) return BigDecimal.valueOf(((Character) value).charValue());
        return new BigDecimal(stringValue(value, true));
    }

    /**
     * Evaluates the given object as a String and trims it if the trim flag is true.
     * 
     * @param value
     *            an object to interpret as a String
     * @return the String value implied by the given object as returned by the toString() method, or
     *         "null" if the object is null.
     */
    public static String stringValue(Object value, boolean trim)
    {
        String result;

        if (value == null) {
            result = OgnlRuntime.NULL_STRING;
        } else {
            result = value.toString();
            if (trim) {
                result = result.trim();
            }
        }
        return result;
    }

    /**
     * Evaluates the given object as a String.
     * 
     * @param value
     *            an object to interpret as a String
     * @return the String value implied by the given object as returned by the toString() method, or
     *         "null" if the object is null.
     */
    public static String stringValue(Object value)
    {
        return stringValue(value, false);
    }

    /**
     * Returns a constant from the NumericTypes interface that represents the numeric type of the
     * given object.
     * 
     * @param value
     *            an object that needs to be interpreted as a number
     * @return the appropriate constant from the NumericTypes interface
     */
    public static int getNumericType(Object value)
    {
        if (value != null) {
            Class c = value.getClass();
            if (c == Integer.class) return INT;
            if (c == Double.class) return DOUBLE;
            if (c == Boolean.class) return BOOL;
            if (c == Byte.class) return BYTE;
            if (c == Character.class) return CHAR;
            if (c == Short.class) return SHORT;
            if (c == Long.class) return LONG;
            if (c == Float.class) return FLOAT;
            if (c == BigInteger.class) return BIGINT;
            if (c == BigDecimal.class) return BIGDEC;
        }
        return NONNUMERIC;
    }

    public static Object toArray(char value, Class toType)
    {
        return toArray(new Character(value), toType);
    }

    public static Object toArray(byte value, Class toType)
    {
        return toArray(new Byte(value), toType);
    }

    public static Object toArray(int value, Class toType)
    {
        return toArray(new Integer(value), toType);
    }

    public static Object toArray(long value, Class toType)
    {
        return toArray(new Long(value), toType);
    }

    public static Object toArray(float value, Class toType)
    {
        return toArray(new Float(value), toType);
    }

    public static Object toArray(double value, Class toType)
    {
        return toArray(new Double(value), toType);
    }

    public static Object toArray(boolean value, Class toType)
    {
        return toArray(new Boolean(value), toType);
    }

    public static Object convertValue(char value, Class toType)
    {
        return convertValue(new Character(value), toType);
    }
    
    public static Object convertValue(byte value, Class toType)
    {
        return convertValue(new Byte(value), toType);
    }
    
    public static Object convertValue(int value, Class toType)
    {
        return convertValue(new Integer(value), toType);
    }
    
    public static Object convertValue(long value, Class toType)
    {
        return convertValue(new Long(value), toType);
    }
    
    public static Object convertValue(float value, Class toType)
    {
        return convertValue(new Float(value), toType);
    }
    
    public static Object convertValue(double value, Class toType)
    {
        return convertValue(new Double(value), toType);
    }
    
    public static Object convertValue(boolean value, Class toType)
    {
        return convertValue(new Boolean(value), toType);
    }
    
    ////////////////////////////////////////////////////////////////
    
    public static Object convertValue(char value, Class toType, boolean preventNull)
    {
        return convertValue(new Character(value), toType, preventNull);
    }
    
    public static Object convertValue(byte value, Class toType, boolean preventNull)
    {
        return convertValue(new Byte(value), toType, preventNull);
    }
    
    public static Object convertValue(int value, Class toType, boolean preventNull)
    {
        return convertValue(new Integer(value), toType, preventNull);
    }
    
    public static Object convertValue(long value, Class toType, boolean preventNull)
    {
        return convertValue(new Long(value), toType, preventNull);
    }
    
    public static Object convertValue(float value, Class toType, boolean preventNull)
    {
        return convertValue(new Float(value), toType, preventNull);
    }
    
    public static Object convertValue(double value, Class toType, boolean preventNull)
    {
        return convertValue(new Double(value), toType, preventNull);
    }
    
    public static Object convertValue(boolean value, Class toType, boolean preventNull)
    {
        return convertValue(new Boolean(value), toType, preventNull);
    }

    /////////////////////////////////////////////////////////////////


    public static Object toArray(char value, Class toType, boolean preventNull)
    {
        return toArray(new Character(value), toType, preventNull);
    }

    public static Object toArray(byte value, Class toType, boolean preventNull)
    {
        return toArray(new Byte(value), toType, preventNull);
    }

    public static Object toArray(int value, Class toType, boolean preventNull)
    {
        return toArray(new Integer(value), toType, preventNull);
    }

    public static Object toArray(long value, Class toType, boolean preventNull)
    {
        return toArray(new Long(value), toType, preventNull);
    }

    public static Object toArray(float value, Class toType, boolean preventNull)
    {
        return toArray(new Float(value), toType, preventNull);
    }

    public static Object toArray(double value, Class toType, boolean preventNull)
    {
        return toArray(new Double(value), toType, preventNull);
    }

    public static Object toArray(boolean value, Class toType, boolean preventNull)
    {
        return toArray(new Boolean(value), toType, preventNull);
    }


    /**
     * Returns the value converted numerically to the given class type This method also detects when
     * arrays are being converted and converts the components of one array to the type of the other.
     * 
     * @param value
     *            an object to be converted to the given type
     * @param toType
     *            class type to be converted to
     * @return converted value of the type given, or value if the value cannot be converted to the
     *         given type.
     */
    public static Object convertValue(Object value, Class toType)
    {
        return convertValue(value, toType, false);
    }

    public static Object toArray(Object value, Class toType)
    {
        return toArray(value, toType, false);
    }
    
    public static Object toArray(Object value, Class toType, boolean preventNulls)
    {
        if (value == null)
            return null;
        
        Object result = null;
        
        if (value.getClass().isArray() && toType.isAssignableFrom(value.getClass().getComponentType()))
            return value;

        if (!value.getClass().isArray()) {
            
            if (toType == Character.TYPE)
                return stringValue(value).toCharArray();
            
            if (value instanceof Collection)
                return ((Collection)value).toArray((Object[])Array.newInstance(toType, 0));

            Object arr =  Array.newInstance(toType, 1);
            Array.set(arr, 0, convertValue(value, toType, preventNulls));

            return arr;
        }
        
        result = Array.newInstance(toType, Array.getLength(value));
        for(int i = 0, icount = Array.getLength(value); i < icount; i++) {
            Array.set(result, i, convertValue(Array.get(value, i), toType));
        }
        
        if (result == null && preventNulls)
            return value;

        return result;
    }

    public static Object convertValue(Object value, Class toType, boolean preventNulls)
    {
        Object result = null;
        
        if (value != null && toType.isAssignableFrom(value.getClass()))
            return value;
        
        if (value != null) {
            /* If array -> array then convert components of array individually */
            if (value.getClass().isArray() && toType.isArray()) {
                Class componentType = toType.getComponentType();

                result = Array.newInstance(componentType, Array.getLength(value));
                for(int i = 0, icount = Array.getLength(value); i < icount; i++) {
                    Array.set(result, i, convertValue(Array.get(value, i), componentType));
                }
            } else if (value.getClass().isArray() && !toType.isArray()) {
                
                return convertValue(Array.get(value, 0), toType);
            } else if (!value.getClass().isArray() && toType.isArray()){
                
                if (toType.getComponentType() == Character.TYPE) {

                    result = stringValue(value).toCharArray();
                } else if (toType.getComponentType() == Object.class) {
                    if (value instanceof Collection) {
                        Collection vc = (Collection) value;
                        return vc.toArray(new Object[0]);
                    } else
                        return new Object[] { value };
                }
            } else {
                if ((toType == Integer.class) || (toType == Integer.TYPE)) {
                    result = new Integer((int) longValue(value));
                }
                if ((toType == Double.class) || (toType == Double.TYPE)) result = new Double(doubleValue(value));
                if ((toType == Boolean.class) || (toType == Boolean.TYPE))
                    result = booleanValue(value) ? Boolean.TRUE : Boolean.FALSE;
                if ((toType == Byte.class) || (toType == Byte.TYPE)) result = new Byte((byte) longValue(value));
                if ((toType == Character.class) || (toType == Character.TYPE))
                    result = new Character((char) longValue(value));
                if ((toType == Short.class) || (toType == Short.TYPE)) result = new Short((short) longValue(value));
                if ((toType == Long.class) || (toType == Long.TYPE)) result = new Long(longValue(value));
                if ((toType == Float.class) || (toType == Float.TYPE)) result = new Float(doubleValue(value));
                if (toType == BigInteger.class) result = bigIntValue(value);
                if (toType == BigDecimal.class) result = bigDecValue(value);
                if (toType == String.class) result = stringValue(value);
            }
        } else {
            if (toType.isPrimitive()) {
                result = OgnlRuntime.getPrimitiveDefaultValue(toType);
            } else if (preventNulls && toType == Boolean.class) {
                result = Boolean.FALSE;
            } else if (preventNulls && Number.class.isAssignableFrom(toType)){
                result = OgnlRuntime.getNumericDefaultValue(toType);
            }
        }
        
        if (result == null && preventNulls)
            return value;

        if (value != null && result == null) {
            
            throw new IllegalArgumentException("Unable to convert type " + value.getClass().getName() + " of " + value + " to type of " + toType.getName());
        }

        return result;
    }

    /**
     * Converts the specified value to a primitive integer value.
     *
     * <ul>
     *  <li>Null values will cause a -1 to be returned.</li>
     *  <li>{@link Number} instances have their intValue() methods invoked.</li>
     *  <li>All other types result in calling Integer.parseInt(value.toString());</li>
     * </ul>
     *
     * @param value
     *          The object to get the value of.
     * @return A valid integer.
     */
    public static int getIntValue(Object value)
    {
        try
        {
            if (value == null)
                return -1;

            if (Number.class.isInstance(value)) {

                return ((Number)value).intValue();
            }

            String str = String.class.isInstance(value) ? (String)value : value.toString();
            
            return Integer.parseInt(str);
        }
        catch (Throwable t)
        {
            throw new RuntimeException("Error converting " + value + " to integer:", t);
        }
    }

    /**
     * Returns the constant from the NumericTypes interface that best expresses the type of a
     * numeric operation on the two given objects.
     * 
     * @param v1
     *            one argument to a numeric operator
     * @param v2
     *            the other argument
     * @return the appropriate constant from the NumericTypes interface
     */
    public static int getNumericType(Object v1, Object v2)
    {
        return getNumericType(v1, v2, false);
    }

    /**
     * Returns the constant from the NumericTypes interface that best expresses the type of an
     * operation, which can be either numeric or not, on the two given types.
     * 
     * @param t1
     *            type of one argument to an operator
     * @param t2
     *            type of the other argument
     * @param canBeNonNumeric
     *            whether the operator can be interpreted as non-numeric
     * @return the appropriate constant from the NumericTypes interface
     */
    public static int getNumericType(int t1, int t2, boolean canBeNonNumeric)
    {
        if (t1 == t2) return t1;

        if (canBeNonNumeric && (t1 == NONNUMERIC || t2 == NONNUMERIC || t1 == CHAR || t2 == CHAR)) return NONNUMERIC;

        if (t1 == NONNUMERIC) t1 = DOUBLE; // Try to interpret strings as doubles...
        if (t2 == NONNUMERIC) t2 = DOUBLE; // Try to interpret strings as doubles...

        if (t1 >= MIN_REAL_TYPE) {
            if (t2 >= MIN_REAL_TYPE) return Math.max(t1, t2);
            if (t2 < INT) return t1;
            if (t2 == BIGINT) return BIGDEC;
            return Math.max(DOUBLE, t1);
        } else if (t2 >= MIN_REAL_TYPE) {
            if (t1 < INT) return t2;
            if (t1 == BIGINT) return BIGDEC;
            return Math.max(DOUBLE, t2);
        } else return Math.max(t1, t2);
    }

    /**
     * Returns the constant from the NumericTypes interface that best expresses the type of an
     * operation, which can be either numeric or not, on the two given objects.
     * 
     * @param v1
     *            one argument to an operator
     * @param v2
     *            the other argument
     * @param canBeNonNumeric
     *            whether the operator can be interpreted as non-numeric
     * @return the appropriate constant from the NumericTypes interface
     */
    public static int getNumericType(Object v1, Object v2, boolean canBeNonNumeric)
    {
        return getNumericType(getNumericType(v1), getNumericType(v2), canBeNonNumeric);
    }

    /**
     * Returns a new Number object of an appropriate type to hold the given integer value. The type
     * of the returned object is consistent with the given type argument, which is a constant from
     * the NumericTypes interface.
     * 
     * @param type
     *            the nominal numeric type of the result, a constant from the NumericTypes interface
     * @param value
     *            the integer value to convert to a Number object
     * @return a Number object with the given value, of type implied by the type argument
     */
    public static Number newInteger(int type, long value)
    {
        switch(type) {
        case BOOL:
        case CHAR:
        case INT:
            return new Integer((int) value);

        case FLOAT:
            if ((long) (float) value == value) { return new Float((float) value); }
            // else fall through:
        case DOUBLE:
            if ((long) (double) value == value) { return new Double((double) value); }
            // else fall through:
        case LONG:
            return new Long(value);

        case BYTE:
            return new Byte((byte) value);

        case SHORT:
            return new Short((short) value);

        default:
            return BigInteger.valueOf(value);
        }
    }

    /**
     * Returns a new Number object of an appropriate type to hold the given real value. The type of
     * the returned object is always either Float or Double, and is only Float if the given type tag
     * (a constant from the NumericTypes interface) is FLOAT.
     * 
     * @param type
     *            the nominal numeric type of the result, a constant from the NumericTypes interface
     * @param value
     *            the real value to convert to a Number object
     * @return a Number object with the given value, of type implied by the type argument
     */
    public static Number newReal(int type, double value)
    {
        if (type == FLOAT) return new Float((float) value);
        return new Double(value);
    }

    public static Object binaryOr(Object v1, Object v2)
    {
        int type = getNumericType(v1, v2);
        if (type == BIGINT || type == BIGDEC) return bigIntValue(v1).or(bigIntValue(v2));
        return newInteger(type, longValue(v1) | longValue(v2));
    }

    public static Object binaryXor(Object v1, Object v2)
    {
        int type = getNumericType(v1, v2);
        if (type == BIGINT || type == BIGDEC) return bigIntValue(v1).xor(bigIntValue(v2));
        return newInteger(type, longValue(v1) ^ longValue(v2));
    }

    public static Object binaryAnd(Object v1, Object v2)
    {
        int type = getNumericType(v1, v2);
        if (type == BIGINT || type == BIGDEC) return bigIntValue(v1).and(bigIntValue(v2));
        return newInteger(type, longValue(v1) & longValue(v2));
    }
    
    public static boolean equal(Object v1, Object v2)
    {
        if (v1 == null) return v2 == null;
        if (v1 == v2 || isEqual(v1, v2)) return true;
        if (v1 instanceof Number && v2 instanceof Number)
            return ((Number) v1).doubleValue() == ((Number) v2).doubleValue();
        return false;
    }

    public static boolean less(Object v1, Object v2)
    {
        return compareWithConversion(v1, v2) < 0;
    }

    public static boolean greater(Object v1, Object v2)
    {
        return compareWithConversion(v1, v2) > 0;
    }

    public static boolean in(Object v1, Object v2)
        throws OgnlException
    {
        if (v2 == null) // A null collection is always treated as empty
            return false;

        ElementsAccessor elementsAccessor = OgnlRuntime.getElementsAccessor(OgnlRuntime.getTargetClass(v2));
        
        for(Enumeration e = elementsAccessor.getElements(v2); e.hasMoreElements();) {
            Object o = e.nextElement();

            if (equal(v1, o)) 
                return true;
        }
        
        return false;
    }

    public static Object shiftLeft(Object v1, Object v2)
    {
        int type = getNumericType(v1);
        if (type == BIGINT || type == BIGDEC) return bigIntValue(v1).shiftLeft((int) longValue(v2));
        return newInteger(type, longValue(v1) << (int) longValue(v2));
    }

    public static Object shiftRight(Object v1, Object v2)
    {
        int type = getNumericType(v1);
        if (type == BIGINT || type == BIGDEC) return bigIntValue(v1).shiftRight((int) longValue(v2));
        return newInteger(type, longValue(v1) >> (int) longValue(v2));
    }

    public static Object unsignedShiftRight(Object v1, Object v2)
    {
        int type = getNumericType(v1);
        if (type == BIGINT || type == BIGDEC) return bigIntValue(v1).shiftRight((int) longValue(v2));
        if (type <= INT) return newInteger(INT, ((int) longValue(v1)) >>> (int) longValue(v2));
        return newInteger(type, longValue(v1) >>> (int) longValue(v2));
    }

    public static Object add(Object v1, Object v2)
    {
        int type = getNumericType(v1, v2, true);
        switch(type) {
        case BIGINT:
            return bigIntValue(v1).add(bigIntValue(v2));
        case BIGDEC:
            return bigDecValue(v1).add(bigDecValue(v2));
        case FLOAT:
        case DOUBLE:
            return newReal(type, doubleValue(v1) + doubleValue(v2));
        case NONNUMERIC:
            int t1 = getNumericType(v1),
            t2 = getNumericType(v2);
            
            if (((t1 != NONNUMERIC) && (v2 == null)) || ((t2 != NONNUMERIC) && (v1 == null))) {
                throw new NullPointerException("Can't add values " + v1 + " , " + v2);
            }

            return stringValue(v1) + stringValue(v2);
        default:
            return newInteger(type, longValue(v1) + longValue(v2));
        }
    }

    public static Object subtract(Object v1, Object v2)
    {
        int type = getNumericType(v1, v2);
        switch(type) {
        case BIGINT:
            return bigIntValue(v1).subtract(bigIntValue(v2));
        case BIGDEC:
            return bigDecValue(v1).subtract(bigDecValue(v2));
        case FLOAT:
        case DOUBLE:
            return newReal(type, doubleValue(v1) - doubleValue(v2));
        default:
            return newInteger(type, longValue(v1) - longValue(v2));
        }
    }

    public static Object multiply(Object v1, Object v2)
    {
        int type = getNumericType(v1, v2);
        switch(type) {
        case BIGINT:
            return bigIntValue(v1).multiply(bigIntValue(v2));
        case BIGDEC:
            return bigDecValue(v1).multiply(bigDecValue(v2));
        case FLOAT:
        case DOUBLE:
            return newReal(type, doubleValue(v1) * doubleValue(v2));
        default:
            return newInteger(type, longValue(v1) * longValue(v2));
        }
    }

    public static Object divide(Object v1, Object v2)
    {
        int type = getNumericType(v1, v2);
        switch(type) {
        case BIGINT:
            return bigIntValue(v1).divide(bigIntValue(v2));
        case BIGDEC:
            return bigDecValue(v1).divide(bigDecValue(v2), BigDecimal.ROUND_HALF_EVEN);
        case FLOAT:
        case DOUBLE:
            return newReal(type, doubleValue(v1) / doubleValue(v2));
        default:
            return newInteger(type, longValue(v1) / longValue(v2));
        }
    }

    public static Object remainder(Object v1, Object v2)
    {
        int type = getNumericType(v1, v2);
        switch(type) {
        case BIGDEC:
        case BIGINT:
            return bigIntValue(v1).remainder(bigIntValue(v2));
        default:
            return newInteger(type, longValue(v1) % longValue(v2));
        }
    }

    public static Object negate(Object value)
    {
        int type = getNumericType(value);
        switch(type) {
        case BIGINT:
            return bigIntValue(value).negate();
        case BIGDEC:
            return bigDecValue(value).negate();
        case FLOAT:
        case DOUBLE:
            return newReal(type, -doubleValue(value));
        default:
            return newInteger(type, -longValue(value));
        }
    }

    public static Object bitNegate(Object value)
    {
        int type = getNumericType(value);
        switch(type) {
        case BIGDEC:
        case BIGINT:
            return bigIntValue(value).not();
        default:
            return newInteger(type, ~longValue(value));
        }
    }

    public static String getEscapeString(String value)
    {
        StringBuffer result = new StringBuffer();

        for(int i = 0, icount = value.length(); i < icount; i++) {
            result.append(getEscapedChar(value.charAt(i)));
        }
        return new String(result);
    }

    public static String getEscapedChar(char ch)
    {
        String result;

        switch(ch) {
        case '\b':
            result = "\b";
            break;
        case '\t':
            result = "\\t";
            break;
        case '\n':
            result = "\\n";
            break;
        case '\f':
            result = "\\f";
            break;
        case '\r':
            result = "\\r";
            break;
        case '\"':
            result = "\\\"";
            break;
        case '\'':
            result = "\\\'";
            break;
        case '\\':
            result = "\\\\";
            break;
        default:
            if (Character.isISOControl(ch)) {

                String hc = Integer.toString((int) ch, 16);
                int hcl = hc.length();

                result = "\\u";
                if (hcl < 4) {
                    if (hcl == 3) {
                        result = result + "0";
                    } else {
                        if (hcl == 2) {
                            result = result + "00";
                        } else {
                            result = result + "000";
                        }
                    }
                }
                
                result = result + hc;
            } else {
                result = new String(ch + "");
            }
            break;
        }
        return result;
    }

    public static Object returnValue(Object ignore, Object returnValue)
    {
        return returnValue;
    }

    /**
     * Utility method that converts incoming exceptions to {@link RuntimeException} 
     * instances - or casts them if they already are.
     *
     * @param t
     *      The exception to cast.
     * @return The exception cast to a {@link RuntimeException}.
     */
    public static RuntimeException castToRuntime(Throwable t)
    {
        if (RuntimeException.class.isInstance(t))
            return (RuntimeException)t;

        if (OgnlException.class.isInstance(t))
            throw new UnsupportedCompilationException("Error evluating expression: " + t.getMessage(), t);
        
        return new RuntimeException(t);
    }
}
